COPPER AND NICKEL RECOVERY WITH CHELATED ION EXCHANGE RESINS. BEFORE/AFTER PHOTO (alkaline etchant, electroless copper, electroless nickel)

The recovery of Copper, Nickel, Lead, Zinc and other heavy metals from solutions can be simplified by using a chelated resin. The picture above shows three solutions, a concentrated electroless nickel, a 5% electroless coppper and a 10% alkaline etchant. Each solution is shown in the native state and with a chelated resin added. The Nickel and Alkaline etchant are clear and the electroless copper still shows a bit of blue. It is hard to see the after color in the picture due to the bright blue next to each jar. These solutions are at equilibrium and therefore, some metal still is in solution. This demonstration is to show that the resin has affinity for metals in chelated solutions and the equilibrium is in favor of the resin.

In normal operation, there is no equilibrium formed as the resin is in a column and the solution travels through the column and continually sees fresh resin before exiting. Toward the end of a cycle, when there is little fresh resin left, "leakage" starts to increase and the resin is regenerated.

These examples are shown to demonstrating the capability of the resins. Each type of chelated resin has it's own special capability.

In normal operation treating rinse waters, limits of 0-20 parts per billion are achieved at high flow rates and up to 300 ppm dissolved metals entering the system.

In systems where metal is to be recovery for it's value, high input concentrations up to 10g/l with regenerant concentrations between 50 and 100 g/l is possible.

Go to (Ion Exchange metal removal and recovery systems efficiency graph (24k gif)) to see actual operational effluent measurements from one system that is 15 years old this year (2007) and is still operating.